In drilling and completion of subterranean wells, such as oil and gas wells, it is often important to monitor the physical conditions inside the borehole of an oil well, in order to ensure proper operations of the well. However, it can be difficult for operators to perform accurate bottom hole measurements. For example, bottom hole pressure data calculated from surface pressure is inaccurate for applications other than gross behavior (e.g., screen out, ball seats, etc.).
The instrumentation of wells using fiber optics-based distributed systems such as distributed temperature sensing (DTS), distributed acoustic sensing (DAS), and other sensing systems based on for example interferometric sensing is well established. Optical fiber can be run on the outside of tubing to the surface, where interrogators detect reflected light from the entire length of the fiber and/or single/multi point sensors. However, in some cases there are structures in the well which prevent, or make difficult, fiber from being installed over the entire length of the string, or at least overall regions of interest. For example, during multi-zone fracturing operations, packers and/or bridge plugs will be used in a cased well to isolate zones for separate perforating and/or fracturing, and will often include sequential isolation of multiple zones within the well has the perforating and fracturing is performed. These packers and bridge plugs preclude passage of a fiber through the interior of the casing. As a result, downhole measurements are difficult during such hydraulic fracturing and the following initial shut-in periods, as it is not feasible to provide physical communication with downhole sensors, such as through wireline, fiber-optic cable, coiled tubing, etc. within the casing.